In this continuation we propose to continue genetic analysis of the HSV-1 cour gene that is located in the BamHI F fragment near map unit 0.645. We are able to assay the affects of expression of this HV-1 DNA in E. coli and are able to select viral mutants based on the loss of induced phenotype in E. coli after plasmid mutagenesis. We will also study the colinear HSV-1 59K protein gene and HSV-2 61K protein gene that map near position 0.60. The function of these proteins in the lytic cycle is unknown; however, the expression of the carboxy terminus of the HSV-1 gene can be assayed in E. coli. In these experiments we will use a novel point mutant selection technique by assay of mutated inserts aligned as alternate reading frames in ORF vectors and combine this technique with assays of induced phenotypes in the correct frame to select the most appropriate mutants for transfer to the HSV-1 and HSV-2 genomes. The mechanism of HSV-2 neoplastic transformation by the direct repeat DNA of the mtrII will be further investigated by the analysis of the transforming 73:2.1 extrachromosomal element, pEX 73:2.1. We have identified mos oncogene homology in close association with the direct repeat DNA of the mtrII in pEX73:2.1 and mos oncogene homology to a colinear region of the HSV-1 and HSV-2 genomes. We propose a structural and functional analysis of pEX73:2.1 in order to discern the mechanism of mos activation by the direct repeat DNA and determine the functional relationship of genes at the HSV-2 genomic mos homology with the mtrII direct repeat DNA.